The present invention relates to an ink cartridge for use in an inkjet-type recording apparatus that ejects ink droplets by nozzles, and records an image, a character and the like on a recording sheet, and relates to a recording apparatus including the ink cartridge.
At present, a large number of inkjet-type recording apparatuses (inkjet printers), each of which ejects ink droplets on a recorded medium such as a recording sheet, and records an image, a character and the like thereon, are provided. Each of these inkjet printers supplies ink to a recording head through an ink supply tube from a main tank in an inside of which the ink is hermetically filled in advance, and ejects the ink droplets from nozzles of the recording head on the recording sheet, thereby performs such recording.
As a type of the inkjet printers as described above, there is one in which a sub tank serving as an ink container with a smaller capacity than that of the main tank is provided between the main tank and the nozzles. In this type of the inkjet printer, the ink that is caused to flow out of the main tank is temporarily stored in the sub tank, and the stored ink is supplied from the sub tank to the nozzles.
In the inkjet printer including the sub tank, in order that the ink can always be supplied from the sub tank to the nozzles, it is necessary to grasp a residual amount of the ink in the sub tank, and to supply a fixed amount of the ink from the main tank to the sub tank when the ink in the sub tank runs out. As a mechanism for this purpose, for example, an ink residual amount detection mechanism described in Patent Document 1 is known.
The ink residual amount detection mechanism described in JP 2003-112433 A includes: a base member of a fixing system; a container (ink bag) that is freely expansible or contractible in response to a change of an amount of liquid ink stored in an inside thereof, in which one side thereof is disposed on the base member; a moving member (plate) that is disposed on the other side of the container so that the container can be located between the moving member concerned and the base member, and moves in response to the expansion or contraction of the container; a first detecting means for detecting one of end portions of the moving member that moves as the container expands by an increase of the amount of ink; a second detecting means for detecting the other end portion of the moving member that moves as the container contracts by a decrease of the amount of ink; and an abutting member against which the other end portion of the moving member that moves as the container expands by the increase of the amount of ink abuts.
Specifically, in the ink residual amount detection mechanism described in JP 2003-112433 A, the flexible ink bag is used as the sub tank, one of side surfaces of the ink bag is directly adhered onto the base member fixed to the inkjet printer, and the another side surface is adhered onto the moving member. Then, when the ink in the inside of the ink bag is decreased to a preset minimum amount or less, the other end portion of the moving member is detected by the second detecting means, and the ink is caused to flow into the ink bag from the main tank. After that, when the ink is caused to flow into the ink bag up to a preset maximum amount, the one end portion of the moving member is detected by the first detecting means, and such inflow of the ink is stopped.
In accordance with the mechanism as described above, the ink is always stored in the inside of the ink bag, and accordingly, the ink can always be supplied to the nozzles from the ink bag serving as the sub tank.
Incidentally, even with the above-mentioned ink bag that is used as the sub tank and supplied with the ink from the main tank, it is necessary to periodically exchange the ink bag since the ink bag itself is deteriorated with time.
However, the ink container for use in the above-mentioned ink residual amount detection mechanism described in Patent Document 1 is not one in which the ink bag is housed in a housing, but one in which the ink bag is directly adhered onto the inkjet printer, and accordingly, it has taken a lot of time and labor to exchange the ink bag. In addition, it has been necessary to accurately fix the ink bag to a predetermined position of the base member. In the case where the position to which the ink bag is fixed shifts from the predetermined position, the moving member adhered onto the ink bag is not accurately positioned with respect to the detecting means, and it has been possible that erroneous detection may occur regarding the residual amount of ink.